def semicolon(self, stmt):
if not isinstance(stmt, _ast.If) and not isinstance(stmt, _ast.While) and not isinstance(stmt, _ast.For):
return ";"
else:
return ""
python类While()的实例源码
def handleNodeDelete(self, node):
def on_conditional_branch():
"""
Return `True` if node is part of a conditional body.
"""
current = getattr(node, 'parent', None)
while current:
if isinstance(current, (ast.If, ast.While, ast.IfExp)):
return True
current = getattr(current, 'parent', None)
return False
name = getNodeName(node)
if not name:
return
if on_conditional_branch():
# We cannot predict if this conditional branch is going to
# be executed.
return
if isinstance(self.scope, FunctionScope) and name in self.scope.globals:
self.scope.globals.remove(name)
else:
try:
del self.scope[name]
except KeyError:
self.report(messages.UndefinedName, node, name)
def handleNodeDelete(self, node):
def on_conditional_branch():
"""
Return `True` if node is part of a conditional body.
"""
current = getattr(node, 'parent', None)
while current:
if isinstance(current, (ast.If, ast.While, ast.IfExp)):
return True
current = getattr(current, 'parent', None)
return False
name = getNodeName(node)
if not name:
return
if on_conditional_branch():
# We cannot predict if this conditional branch is going to
# be executed.
return
if isinstance(self.scope, FunctionScope) and name in self.scope.globals:
self.scope.globals.remove(name)
else:
try:
del self.scope[name]
except KeyError:
self.report(messages.UndefinedName, node, name)
def handleNodeDelete(self, node):
def on_conditional_branch():
"""
Return `True` if node is part of a conditional body.
"""
current = getattr(node, 'parent', None)
while current:
if isinstance(current, (ast.If, ast.While, ast.IfExp)):
return True
current = getattr(current, 'parent', None)
return False
name = getNodeName(node)
if not name:
return
if on_conditional_branch():
# We can not predict if this conditional branch is going to
# be executed.
return
if isinstance(self.scope, FunctionScope) and name in self.scope.globals:
self.scope.globals.remove(name)
else:
try:
del self.scope[name]
except KeyError:
self.report(messages.UndefinedName, node, name)
def while_loop(self, instr, loop_block):
kw = dict(lineno=instr.lineno, col_offset=0)
loop_block_map = {instr.i:instr.op for instr in loop_block}
first_i = loop_block[0].i
func = lambda instr: instr.opname == 'JUMP_ABSOLUTE' and instr.oparg == first_i
body_index = rfind_index(loop_block[:-1], func)
if body_index is None:
const_while = True
body_index = len(loop_block) - 1
else:
if body_index + 1 < len(loop_block):
pop_block = loop_block[body_index + 1]
const_while = pop_block.opname != 'POP_BLOCK'
const_else = True
else:
const_while = True
const_else = False
if const_while:
test = _ast.Num(1, **kw)
body_ = self.decompile_block(loop_block[:body_index]).stmnt()
else_block = loop_block[body_index + 1:]
if else_block:
else_ = self.decompile_block(else_block).stmnt()
else:
else_ = []
else:
pop_block = loop_block[body_index + 1]
func = lambda instr: instr.opname in ['POP_JUMP_IF_FALSE', 'POP_JUMP_IF_TRUE'] and instr.oparg == pop_block.i
idx = rfind_index(loop_block[:body_index], func)
cond_block = loop_block[:idx]
iter_stmnt = self.decompile_block(cond_block).stmnt()
assert len(iter_stmnt) == 1
test = iter_stmnt[0]
body_ = self.decompile_block(loop_block[idx + 1:body_index]).stmnt()
else_block = loop_block[body_index + 2:]
if else_block:
else_ = self.decompile_block(else_block[:]).stmnt()
else:
else_ = []
while_ = _ast.While(test=test, body=body_, orelse=else_, **kw)
self.ast_stack.append(while_)
